Endophytic Aspergillus Fumigatus Research Articles

Obtaining Diverse Metabolic Profiles from Endophytic Aspergillus fumigatus in Astragalus membranaceus Using the One Strain–Many Compounds Method

Obtaining Diverse Metabolic Profiles from Endophytic Aspergillus fumigatus in Astragalus membranaceus Using the One Strain–Many Compounds Method

Agro-industrial wastes for production of paclitaxel by irradiated Aspergillus fumigatus under solid-state fermentation.

Paclitaxel is the most profitable drug ever developed in cancer chemotherapy; however, the yield of paclitaxel from microbial platforms is still far from the commercial purpose. Thus, this study was conducted to explore the possibility of solid-state fermentation (SSF) for production of paclitaxel by fungal fermentation. Different agro-industrial wastes were screened as solid substrates for production of paclitaxel by the endophytic Aspergillus fumigatus TXD105 under SSF. Sugarcane bagasse followed by wheat bran, and rice bran were the most suitable substrates for maximum production of paclitaxel. In the effort to increase the paclitaxel production, selection of the most proper moistening agent that supports the production of paclitaxel by the fungal strain was investigated. The effect of varying inoculum concentrations on the production of paclitaxel was also studied. Moreover, optimization of SSF conditions (moisture level, substrate concentrations and nutrients concentration) was adopted using response surface methodology. SSF carried out under the optimum conditions of 20g sugarcane bagasse, twofold nutrients concentration of the MM1D broth, 80% moisture level and inoculum concentration of 107 spores per ml intensified the paclitaxel concentration to 145·61mgkg-1 which represents a 10-fold increase. The production of paclitaxel by the fungal strain was further improved via exposure to UV and gamma radiation at specific doses. The paclitaxel concentrations were intensified following UV and gamma radiation to 209·91 and 351·82mgkg-1 . This is the first report on the production of paclitaxel using agro-industrial wastes as cheap source that may contribute in lowering the cost of producing paclitaxel. These findings offer new and alternate sources with excellent biotechnological potential for paclitaxel production by fungal fermentation.

A styrene antioxidant NFA from riparian endophytic fungi enhances flooding tolerance in Arabidopsis

ABSTRACT Flooding is an important limiting factor for plant growth and development. Recent studies have shown that endophytic fungi symbiotic with extreme environmental plants can help hosts resisting various stresses. Previously, a styrene antioxidant NFA (Z-N-(4-hydroxystyryl) formamide) in riparian endophytic Aspergillus fumigatus was reported to effectively improve drought resistance in rice. To evaluate NFA’s ability to resist flooding of plants, we tested the antioxidant activity in yeasts, and investigated the flooding tolerance of Arabidopsis seedlings through fully submergence. The results showed that NFA could effectively alleviated oxidative damage by H2O2 in yeast and improved the flooding resistance of Arabidopsis. The tendency of oxidative parameters responded to flooding can be reversed by NFA, such as malondialdehyde, superoxide dismutase, ethanol dehydrogenase and NADPH oxidase. Expression analyses of NADPH oxidases and ROP protein families indicated that Atrboh D, Atrboh F and AtROP 11 may be involved in NFA-mediated flooding resistance.

A coumarin analogue NFA from endophytic Aspergillus fumigatus improves drought resistance in rice as an antioxidant

BackgroundDrought and its resulting oxidative damage are the major yield limiting factors for crops in arid and semi-arid regions. Recent studies have found that endophytic fungi coexisting in plants can alleviate biotic or abiotic damage to plant growth and development. In order to screen for the endophytes associated with drought stress, 12 strains of endophytic fungi with high antioxidant activity isolated from riparian plants Myricaria laxiflora were evaluated for their effects in rice by the crude extracts.ResultsOf the 12 endophytic fungi, Aspergillus fumigatus SG-17 functioned most effectively, with the crude extract exhibiting relatively higher antioxidant capacity both in vivo and in vitro. The subsequent MS and NMR analysis showed that the primary substance responsible for the antioxidant activity in the extract was (Z)-N-(4-hydroxystyryl) formamide (NFA), an analogue of coumarin. Enzyme activity assay in nerve cells SH-SY5Y showed that NFA could maintain the membrane integrity and regulate the antioxidase activity under oxidative stress. In rice suffering drought stress, NFA effectively alleviated the harm by regulating the contents of NADPH oxidases, antioxidants and heat shock proteins, all of which are closely related with the reactive oxygen species pathway.ConclusionThese findings indicated that some endophytes from plants often subjected to flooding and oxidative stress could enhance drought resistance by producing compounds such as NFA to regulate the oxidative pathway.

Mycosynthesis of Nano-Ag/Ag2O as Anti-Phytopathogens Agent using Endophytic Aspergillus fumigatus Strain EAF102

Mycosynthesis of Nano-Ag/Ag2O as Anti-Phytopathogens Agent using Endophytic Aspergillus fumigatus Strain EAF102

Metabolites from endophytic Aspergillus fumigatus and their in vitro effect against the causal agent of tuberculosis

ABSTRACT Tuberculosis (TB) remains one of the most deadly communicable infectious diseases, causing 1.4 million deaths in 2015 worldwide due to many conditions, including the inadequate treatment and the emergence of multidrug-resistant strains of the causal agent, Mycobacterium tuberculosis. Therefore, drugs developed from natural sources, as microorganisms and plant extracts, are a frequent target for the research and discovery of antimicrobial compounds. The current study started the characterization of compounds produced by an Aspergillus fumigatus isolated from copaíba (Copaifera multijuga) that efficiently inhibits M. tuberculosis by releasing the compounds into the fermentation broth under specific culture conditions. A preliminary assay was carried out with a correlate species, M. smegmatis, aiming to detect an antimicrobial effect related to A. fumigatus fermentation broth. The direct use of this substrate in antibiosis assays againstM. tuberculosis H37Rv strain (ATCC 27294) allowed the detection of antimicrobial activity with a minimal inhibitory concentration of 256 μg mL-1, demonstrating that purification processes developed by the Biotage Flash Chromatography System are robust and reliable techniques for purification of compounds from natural sources. Also, this chromatographic system can be used in combination with specific biochemical tests, improving the search for reliable results. We conclude that this fraction can express a broad action range, inhibiting both Mycobacterium species used as target organisms.

IAA and flavonoids modulates the association between maize roots and phytostimulant endophytic Aspergillus fumigatus greenish

ABSTRACTThe association between microbes and plant roots involves a complex chemical dialogue featured by IAA and flavonoids in addition to other signals. Current study is focused on the role of IAA and flavonoids as essential elements of the chemical dialogue between an endophytic fungus and maize roots. The strain was isolated from the leaves of Withania somnifera and was identified as Aspergillus fumigatus greenish by 18S rDNA sequence. Culture filtrate of the strain contained phyotstimulant (IAA, ammonia and ACC) and signaling compounds including IAA, flavonoids and flavonols. The strain effectively colonized the maize roots and enhanced its growth. In order, to determine the effect of IAA and flavonoids on the ability of the endophyte to colonize maize roots, we inhibited the release of IAA and flavonoids in maize separately which reduced the colonization of endophyte in maize root to 66% and 55% of the untreated control. Similarly, application of IAA in combination with endophyte enhanced root colonization by 90% in zone of cell division, 66% in the zone of elongation and 30% in the zone of maturation. These findings determined that IAA and flavonoids are among the key players of the complex chemical dialogue between plant root and fungal endophyte.

Anti-oxidant and anti-microbial potentials of some metabolites from an endophytic fungi isolated from Lorantus micranthus from south-eastern Nigeria

Endophytes are currently considered as a well spring of novel secondary metabolites; offering the potential for medical, pharmaceutical, agricultural and industrial exploitation. This study aims at assessing the anti-oxidant and antimicrobial activities of the ethyl acetate extract of the metabolites produced by two endophytic fungi isolated from Loranthus micranthus, fermented on rice media. The healthy part of thee leaf was washed under tap water and cut into small fragments of 2 mm length. Stabilization and growth of endophytic fungi, solid state fermentation and isolation of the pure fungi was done following an established standard methods [1, 2]. Phytochemical analysis of the extracts reveals the presence of alkaloids, flavonoids, tannins, reducing sugar, steroids and proteins. The antimicrobial activity of the ethyl acetate extract of the secondary metabolites isolated from endophytic Aspergillus fumigatus identified by cultural and microscopic features was evaluated using the agar well diffusion method. The following test organisms were used; Staphylococcus aureus, Klebsiella pneumoniae, Salmonella typhi, Bacillus subtilis, Candida albicans and A. fumigatus. At the concentrations analyzed (5 – 0.625 mg/mL), the extract recorded only antibacterial and no antifungal activity against the test isolates. Antibacterial activity was observed against all test bacteria at 5 and 2.5 mg/mL; while at 1.25 mg/mL inhibition zone diameters (IZDs) of 2, 2, 0 and 4 mm were recorded against S. aureus, S. typhi, K. pneumoniae and B. subtilis, respectively. At 0.625 mg/mL, antibacterial activity was recorded only against B. subtilis with an IZD of 3 mm. No IZD was recorded against C. albicans and A. fumigatus at the various concentrations analyzed. The extracts exhibited poor DPPH radical scavenging assay activity. The measured DPPH activity at 100 µg was 15.8% – 12% of inhibition as compared to 47 and 74% of inhibition of Rutin and BHT positive controls.

Cytotoxicity of Ethyl Acetate Extract of Endophytic Aspergillus fumigatus on A549 Cell Lines

Endophytes are mutualistic symbionts of healthy plants known for production of wide range of bioactive compounds with a broad spectrum of activity. In the present study, endophytic Aspergillus fumigatus was isolated from Justicia beddomei. The bioactive compounds were extracted with ethyl acetate by solvent extraction procedure. Fraction IV obtained by partial purification with a mixture of hexane and ethyl acetate in silica gel column demonstrated cytotoxicity on A549 and L6 cell lines. The IC 50 was determined to be 8.37 µg/ml and 110.37 µg/ ml respectively by MTT assay. The dual staining and Hoechst staining indicated the induction of apoptosis in the tumor cells. DNA fragmentation further confirmed the DNA of tumor cells as the molecular target of the fraction for cytotoxicity. Further structural characterization studies of the fraction are necessary to reveal the structure –function relationship of the compounds isolated.

Fumigaclavines D-H, new ergot alkaloids from endophytic Aspergillus fumigatus.

Ergot alkaloids are toxins which are produced biotechnologically on an industrial scale. The chemical investigation of endophytic Aspergillus fumigatus resulted in the isolation of five new ergot alkaloids named fumigaclavines D-H (2-6), along with three known analogues, fumigaclavine C (1), festuclavine (7), and fumigaclavine A (8). Their structures were unequivocally elucidated by extensive spectroscopic analyses in association with X-ray single-crystal diffraction. Fumigaclavines D-H are interesting clavine-type ergot alkaloids featuring a reverse prenyl moiety at C-2, with 1-4, 6, and 8 bearing additional substituents, e.g., an OH or OAc group at C-9. Compounds 2, 4, and 6-8 showed a broad spectrum of antimicrobial activity against a panel of anaerobic microorganisms, of which compounds 4 and 6 were the most active against Veillonella parvula with an MIC=16 µg/mL compared to that (0.12 µg/mL) of tinidazole, co-assayed as a positive reference.

Four Ardeemin Analogs from Endophytic Aspergillus fumigatus SPS‐02 and Their Reversal Effects on Multidrug‐Resistant Tumor Cells

Four ardeemin derivatives, 5-N-acetylardeemin (1), 5-N-acetyl-15bβ-hydroxyardeemin (2), 5-N-acetyl-15b-didehydroardeemin (3), and 5-N-acetyl-16α-hydroxyardeemin (4), were isolated from the fermentation broth of an endophytic Aspergillus fumigatus SPS-02 associated with Artemisia annua L. The structures of these metabolites were elucidated by a combination of spectroscopic data, including 1D-, 2D-NMR and MS. In vitro chemosensitization assay indicated that these ardeemins had different activities of reversing the multidrug-resistant (MDR) phenotype in three cancer cell lines, leukemia doxorubicin resistant cell K562/DOX, human lung adenocarcinoma cis-platin-resistant cell A549/DDP, and ovarian cancer cisplatin-resistant cell SK-OV-S/DDP. Compound 4 exhibited the strongest MDR reversing effect at 5 μM concentration in K562/DOX and A549/DDP cell lines 5.2±0.18-fold, 8.2±0.23-fold, respectively, while compound 2 had the highest reversal capacity in SK-OV-S/DDP cell line with 10.8±0.28 fold. Preliminary investigation of their structureactivity relationship suggested that a OH group at C(15b) or C(16) in ardeemin plays a key role in reversing the MDR effect. It is the first report on ardeemin analogs from endophytic A. fumigatus with reversal effects on MDR cancer cell lines K562/DOX, A549/DDP and SK-OV-S/DDP.

Potential allelopathic indole diketopiperazines produced by the plant endophytic Aspergillus fumigatus using the one strain-many compounds method.

On the basis of the OSMAC (one strain-many compounds) strategy, 14 indole diketopiperazine (DKP) alkaloids, including spirotryprostatins (1-3), tryprostatins (4-6), and cyclotryprostatins (7-14), were isolated from the endophyte Aspergillus fumigatus associated with Melia azedarach L. Their structures were identified by nuclear magnetic resonance and electrospray ionization mass spectrometry data. All the indole DKPs were evaluated for plant growth regulation using the lettuce (Lactuca sativa) seedling growth bioassay, which showed the plant growth influence of the seedling. Among these compounds tested, a tryprostatin-type compound, brevianamide F (6), was identified as a new type of natural potential plant growth inhibitor with a response index (RI) higher than that of the positive control glyphosate, a broad-spectrum systemic herbicide. 6 can also inhibit turnip (Raphanus sativus) shoot and root elongation with RIs of -0.76 and -0.70, respectively, at 120 ppm, and it strongly inhibits amaranth (Amaranthus mangostanus) seedling growth with a high RI of -0.9 at 40 ppm. The structure-allelopathic activity relationship analysis of these isolated alkaloids indicates that tryprostatin-type alkaloids without the C5 prenyl and methoxy group give the most potent inhibition of seedling growth. Brevianamide F (6) could be used to develop a natural eco-friendly herbicide.

ChemInform Abstract: Anthraquinone Derivatives from Rumex Plants and Endophytic Aspergillus fumigatus and Their Effects on Diabetic Nephropathy.

AbstractThe oxanthrone C‐glycosides, patientosides A (I*a) and B (I*b), are isolated along with three known ones from Rumex patientia.

Anthraquinone derivatives from Rumex plants and endophytic Aspergillus fumigatus and their effects on diabetic nephropathy

Two new oxanthrone C-glycosides, patientosides A (14) and B (15), together with three known ones (11–13), were isolated from Rumex patientia. Their structures were identified on the basis of spectroscopic methods. The absolute configuration for 14 and 15 were deduced by analysis of their CD spectra and comparison with those of known similar compounds. Compounds 11–15, and 14 known anthraquinones (1–4, 6–10, 16–20) previously isolated from Rumex nepalensis, Rumex hastatus, and endophytic Aspergillus fumigatus, respectively, as well as a commercially available compound rhein (5) were evaluated for their inhibitory effects on IL-6 and extracellular matrix production in mesangial cells.

Medium optimization for enhanced co-production of two bioactive metabolites in the same fermentation by a statistical approach

This paper describes improved optimization method that combines the one-factor-at-a-time method (OFAT), Plackett–Burman design, and the response surface method (RSM), which were used to optimize the medium for the production of fumigaclavine C (FC) and helvolic acid (HA) from endophytic Aspergillus fumigatus CY018 simultaneously. The ideal carbon and nitrogen sources for the two compounds were assessed initially via the one-factor-at-a-time method. Three key cultivation factors (pH, phosphate, and inoculum size) were chosen based on the results of Plackett–Burman design, and subsequently optimized by the central composite design. The two metabolites were amply afforded when the cultivation was carried out with the inoculum size of 2.45% at pH 4.2 and 28°C for 19 days in the medium containing (g/l): mannitol 50, sodium succinate 5.4, NaNO3 2, MgSO4·7H2O 0.3, FeSO4·7H2O 0.01, and KH2PO4 0.67. The highest yields of FC and HA achieved herein were 17.26 and 16.88 mg/l. This work might be the first endeavor leading to the improved simultaneous production of two complex active metabolites with a single strain.

Gibberellins producing endophytic Aspergillus fumigatus sp. LH02 influenced endogenous phytohormonal levels, isoflavonoids production and plant growth in salinity stress

Endophytic fungi are little known for exogenous gibberellins (GAs) production and plant growth promotion under salt stress conditions. We isolated 13 endophytic fungi from soybean roots, which were screened on Waito-C rice for plant growth promoting capacity. Endophytic strain, GMH-1a exhibited maximum growth during screening and thus was investigated for GAs production and host plant interaction. GMH-1a was identified as a new strain of Aspergillus fumigatus sp. LH02 through phylogenetic analysis of 18S rDNA sequence. Analysis of GMH-1a culture filtrate showed presence of GA4 (24.8ng/ml), GA9 (1.2ng/ml) and GA12 (9.8ng/ml). Soybean plants inoculated with GMH-1a significantly increased shoot length, shoot fresh and dry biomass, leaf area, chlorophyll contents and photosynthetic rate under salt stress (70 and 140mM) as compared to non-inoculated plants. GMH-1a inoculated plants had contained significantly lower endogenous abscisic acid (ABA) and elevated free proline, salicylic acid (SA) and jasmonic acid (JA) contents in comparison to their respective control treatments. Isoflavones, quantified through excessive HPLC analysis, showed that GMH-1a inoculated plants with/without salt stress contained higher isoflavones than non-inoculated plants and with/without NaCl stress. This novel endophytic fungus has reprogrammed soybean metabolism to improve plant growth and increase isoflavone contents under salt stress.